This invention relates to automotive display panels, such as dashboards panels, and more particularly to the constructions by which such panels are made visible at night.
Automotive display panels, where "automotive" connotes cars, trucks, motorcycles, and vehicles generally, currently are formed of materials such as clear polycarbonate. The clear polycarbonate is decorated front and back for day and night-time displays. The decoration on the front includes daytime information, on a background, typically black. The daytime information is formed of pigmented inks, screen printed on the panels in desired colors, typically white. The decoration on the back of the panels includes nighttime information, again in pigmented inks, provided to be visible through the panel under back lighting. Decoration on the panel backs allows nighttime colors such as red and green to be different from daytime white.
Compensation is also printed on the panel back. This compensation allows substantially equal brightness across the panel under back lighting, even though the back lighting may be uneven. As an example, some panels are back lit from the side. Further, warning displays known as telltales, are provided, to be visible under illumination of warning lights.
Automotive display panels as described are the standard of the automotive industry, given the rigorous performance standards of that industry. Panels as described are a desirable combination of materials able to survive automotive quality control requirements at affordable pricing. Such quality control requirements include temperature testing for survival in hostile, steady-state heat and freezing; hostile temperature cycling; sustained high humidity; sustained intense lighting; and combinations of lighting, temperature, humidity, and water spray.
This standard of the industry is not without deficiencies and costs. As an example, as indicated, compensation is required for adequately uniform back lighting. However, despite deficiencies and costs, alternative panels and lighting schemes are not known to the commercial automotive industry. Among other screens not known, fluorescent displays are not known. A variety of patents disclose fluorescent lighting of indicia such as automotive instrumentation information, but the inventions of such patents have not been adopted in commercial applications. Inability to satisfy quality control requirements at competitive pricing is believed to be the primary reason for the lack of adoption. Use of ultraviolet lighting which is unsuitable to close proximity to drivers and passengers is believed to further contribute to the situation.